Preliminary tests have failed to pinpoint why students and staff at Riverton Elementary School, 13150 S. 1830 West, are occasionally sickened in the building.

On Feb. 24, 18 students complaining of headaches, nausea, rashes and respiratory difficulty were hospitalized after an unusual odor was detected in the school. The school was evacuated. Since then, the school board ordered the school closed until the problem can be isolated and treated.Meanwhile, students have been bused to three other schools.

Closing the school is not an option, said Superintendent Barry Newbold.